Lighting devices which produce multi-colored light of a certain polarization are useful in many applications, for instance spotlights, stage lighting systems, automotive headlamps and digital light projectors. An example of such a light source is the device for projection displays disclosed in US 2008/0094577 A1. In this device, the light from several light emitting diodes is combined to form polarized light for producing a projected image.
Depending on the application, the lighting device must meet different technical requirements. Many applications require that the intensity of the produced light is high, and the development of high-intensity light sources producing polarized multi-colored light is therefore an important area of applied research.